Need some guidance please with unlock

[ShaggyiPhone]

Need a little guidance and a push in the right direction. Have jailbroken an iPhone in several years

iPhone 3gs. OS version is 4.3.2 Baseband is 05.16.02. Its already jailbroken, cydia installed. I installed ultrasn0w to unlock it but when i put the T-mobile sim it says no service. Ive read through some other forms and from what i have found the baseband can't be unlock and must be upgraded to iPad 6.15.00. Is this correct?, or is there another process that is best. I Also read that I will loose GPS and that it will cause an iTunes error. What is the best iOS for the 3gs? Will iOS 5 run good on it?



Thanks in advance and sorry if this is already posted somewhere. just want to make sure i do this correctly.
-Stephen

[iYeow]

Yes, to unlock you have to update to ipad bb using redsn0w 0.9.6 b17. This is the only way , put redsn0w in xp sp2 compatibility mode. IOS 5 jailbreak will be tethered jailbreak unless if it an old bootrom.

[zedbra]

nvm, answred